List more than 20 items in Media Library

After a few failed attempts of importing a bunch of posts from an other wordpress blog, I’ve ended up with a BIG bunch of photos in the Media Library that are unattached. I need to delete those. I could delete via FTP, but then images are still referenced in the Library.

SO, what I want to do is to list more than 20 items in the media library. I looked into the code under includes, but cant find it.